It has long been a problem in the operation of farm equipment to guide various implements through a crop field, without accidentally deviating from the crop row and destroying planted crops. Various tractor-drawn implements may carry ground working tools spaced as close as 4" apart. The tractor operator is generally situated in a cab located several feet above and forward of the implement, so that it is difficult to view the actual engagement of the tools with the ground. All the operator can do is attempt to keep the tractor centered relative to the rows.
The problem of maintaining the ground working tools between the rows becomes critical in an operation such as cultivating where only a slight lateral misalignment of the tractor with the rows will cause the implement to uproot several rows of crops. This problem is enhanced as the operator .[.speeds.]. .Iadd.spends .Iaddend.many hours in the field following long rows of crops. In the small amount of time it takes to turn from observing the implement to look forward to align the tractor in the rows, a few feet of crops can be uprooted due to a slight misalignment of the implement with the crop row.